feat(podcasts): queue context source + player order control — item 2.2

Foundation rule R2 (§10): the queue context is the only queue, and
every producer emits the same shape. PodcastSequenceContext gains
source (feed|collection), feed_id, and order; the feed producer sets
them now — the collection producer (2.3) slots into the same shape
without the player ever special-casing beyond showing/hiding controls.

The player header gains the FEED-mode order control next to the
"Ep N/M" counter: a dropdown (native/reverse/oldest/newest) plus a
one-click reverse button. Both PUT the existing per-user feed order
override — the SAME state the feed page writes, so flipping it in the
player updates the feed page's dropdown too. The control renders only
when source=feed: a collection queue's order is curated content
(R1), never a listening preference. Behavior is hx-put +
hx-swap="none" (response discarded) with a module-level
htmx:afterRequest listener in audio.ts reloading the page — the
server re-renders prev/next/index in the new order; templ decides
what it looks like, JS only triggers the round trip (CSP-clean, no
inline handlers).

Pinned by TestPodcastPlayerOrderControl: the config JSON carries
source/feed_id/order/episode_index; the control renders feed-mode;
an order override re-renders with the dropdown reflecting it (data-
json pins must match templ's " attribute escaping).

templates/audio_reader.templ

@@ -116,6 +116,38 @@ templ AudioReader(user User, metadata ReaderMetadata) {
 						<span class="text-xs tabular-nums ml-1" style="color: var(--text-secondary)">
 							Ep { fmt.Sprintf("%d", metadata.PodcastSequence.EpisodeIndex) }/{ fmt.Sprintf("%d", metadata.PodcastSequence.IndexTotal) }
 						</span>
+						<!-- Order control (item 2.2, §10 R2): FEED-mode only — a
+						     collection queue's order is curated content, never a
+						     preference (hidden in collection mode). PUTs the same
+						     per-user override the feed page writes; hx-swap="none"
+						     discards the response and web/src/audio.ts reloads so
+						     the server re-renders prev/next/index in the new order. -->
+						if metadata.PodcastSequence.Source == "feed" && metadata.PodcastSequence.FeedID != "" {
+							<select
+								id="player-order-select"
+								name="order"
+								aria-label="Episode order"
+								class="input w-auto py-0.5 text-xs ml-2 cursor-pointer"
+								hx-put={ "/api/podcasts/feeds/" + metadata.PodcastSequence.FeedID + "/order" }
+								hx-swap="none"
+							>
+								<option value="native" selected?={ metadata.PodcastSequence.Order == "native" }>Feed order</option>
+								<option value="reverse" selected?={ metadata.PodcastSequence.Order == "reverse" }>Feed order (reversed)</option>
+								<option value="oldest" selected?={ metadata.PodcastSequence.Order == "oldest" }>Oldest first (pub date)</option>
+								<option value="newest" selected?={ metadata.PodcastSequence.Order == "newest" }>Newest first (pub date)</option>
+							</select>
+							<button
+								type="button"
+								aria-label="Reverse episode order"
+								title="Reverse episode order (start from the feed's beginning)"
+								class="rounded-full p-1.5 hover:bg-surface-hover transition-colors"
+								hx-put={ "/api/podcasts/feeds/" + metadata.PodcastSequence.FeedID + "/order" }
+								hx-vals='{"order": "reverse"}'
+								hx-swap="none"
+							>
+								<svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" style="color: var(--text-secondary)"><path d="M3 12a9 9 0 1 0 9-9 9.75 9.75 0 0 0-6.74 2.74L3 8"/><path d="M3 3v5h5"/></svg>
+							</button>
+						}
 					}
 				</span>
 				<span class="inline-flex items-center gap-2">